The present study will compare the short-term and long-term effectiveness of self-control desensitization, self-control desensitization plus cognitive therapy, and cognitive therapy alone in the treatment of generalized anxiety disorder. Seventy-five clients will be diagnosed for primary generalized anxiety disorder by two independent psychiatric assessors using the Anxiety Disorders Interview Schedule, will complete a variety of pretherapy anxiety questionnaires and daily diaries, and will participate in a psychophysiological laboratory session which assesses peripheral and central physiological activity during several tasks of theoretical relevance to anxiety disorders. Subsequently, they will be provided 14 1.5-hour individual therapy sessions, after which posttherapy assessment will be repeated using the same psychiatric interview, questionnaires and diaries, and laboratory session. Two further therapy sessions will then be provided as fading sessions. Follow-up assessments will take place at 6 months, 12 months, and 24 months, and will include the psychiatric interview and questionnaires and diaries. The therapists will be two Ph.D. clinicians well-experienced in cognitive-behavioral treatment of anxiety disorders. A matched group of 75 nonanxious subjects will participate in the psychiatric interview and questionnaire sessions and will undergo the laboratory session, to provide normative information and as a contrast group for the physiological measures.